When the correct installation, use and maintenance of 4mm banana plug, Plug and socket should be visibly marked rated current, rated voltage, power supply properties. In addition, the converter (converter means only one plug and one or more outlets for mobile electrical parts together. Symbols marked/rated current, or power, to guide the user to avoid overload. Signs or symbols should be durable and clearly visible. Can be easily erased should not be used for screen printing and paper labels.

Protection against electric shock is to ensure that the plug and socket, converter under the normal conditions of use, and even some unexpected circumstances, will not cause the user and others a key safety indicators for electric shock accident. When the plug and socket, in whole or in part, into timely and plug the live parts should be untouchable; 4mm banana plug either bolted in when the other bolt is reached, should not be able to plug the plug with the socket set. With protective plugs, switches should prevent unipolar or probe.